The present invention pertains to processor systems and more particularly to the use of memory devices to dynamically map one or more of a number of input events to one or more of a number of output functions automatically.
In processor systems, it is required of the processor that it interact with external stimuli such as sensors, indicators, timers, etc. Each of these stimuli may initiate or may be initiated by the processor to perform some particular function. Some typical triggering events might include hardware matchers providing an output, counter or timer outputs or interrupt or other logic signals transmitted from or to the processor.
An assignment scheme is required to associate a particular triggering event with a desired functional output. This scheme is accomplished with an event routing scheme. Typically, event routing schemes are accomplished with dedicated connections or with multiplexers. Hard-wired connections allow no flexibility in altering the results for given input pattern. Such a configuration is very limiting for processor application. Implementing an event selection scheme with multiplexers requires full availability of input events at each multiplexer to select the particular output. This scheme needs many hard-wired connections. In addition, this scheme requires a dedicated multiplexer for each output function to be programmed. Having such a large amount of hardware to implement a selection scheme is costly and requires a considerable amount of physical space.